Healthy rice to feed the world

Resistance to the bacterial leaf blight (BLB) disease, caused by the pathogenic bacterium Xanthomonas oryzae pv. oryzae (Xoo), is highly valuable trait in Asia and Africa, where the disease significantly reduces rice yields.

During the infection process, Xanthomonas bacteria inject virulence-promoting proteins, i.e., transcription activator-like effectors (TALEs), into rice cells. These bacterial proteins bind to rice DNA and upregulate transcription of rice genes encoding sucrose transporters. The export of intracellular sucrose by rice sucrose transporters leads to susceptibility to the pathogen. The precise editing of the rice DNA elements exploited by the pathogenic bacteria provides complete and broad resistance to the BLB.

During my postdoctoral study, I aim to utilize advanced biotechnological tools and approaches for the development of elite rice lines with improved resistance to Xoo and other pathogens. Rather than relying on conventional transgene-dependent approaches which lead to introgression of transgene fragments in a plant genome for editing purposes, I’m focused on establishment of transgene-independent (transgene-free) editing of the elements exploited by the pathogenic microorganisms.

Transgene-independent genome editing approach allows direct delivery of editing components in the form of preassembled ribonucleoprotein (protein and RNA) complexes into single rice cells with subsequent regeneration of plant tissue from each edited cell. These ribonucleoprotein complexes are quickly degraded in a rice cell making the process of genome editing fast and short-lived.

Figure 1. (Left) TALE-dependent upregulation of rice genes encoding sucrose transporters leads to susceptibility to Xoo. (Right) Editing of TALE-binding elements prevents binding of TALEs to edited elements and results into a recessive resistance to Xoo.

Planter’s Punch

Under the heading Planter’s Punch we present each month one special aspect of the CEPLAS research programme. All contributions are prepared by our early career researchers.

About the author

Kirill Schenstniy is a postdoctoral researcher in the group of Prof. Dr. Wolf Frommer at the Institute for Molecular Physiology (Heinrich Heine University of Duesseldorf). He is fascinated by biotechnology and is focused on eliminating rice susceptibility genes to enhance its resistance to multiple pathogens. Prior to joining CEPLAS, he completed his PhD in the Center for Plant Molecular Biology (Eberhard Karls University of Tuebingen) where he studied functioning of so-called “executors”, a novel class of bacterial blight resistance proteins from pepper and rice. In his rare free time, he enjoys cooking delicious food, traveling to the seaside, and listening to music.